Page 1537 of 4133

REAR INTERMITTENT WIPE - FUNCTION - GF82.30-P-3001GH
MODEL 163 Applicable to 31.8.00
The rear intermittent wipe function is activated by placing the rear wiper/washer switch (S78) in the up
position. With the switch in this position, the All Activity Module (AAM) (N10) activates the tailgate wiper
motor (M6/4) every five seconds.
A relay circuit in the wiper motor stops the wiper arm in the park position.
REAR INTERMITTENT WIPE - FUNCTION - GF82.30-P-3001GK
MODEL 163 Applicable as of 1.9.00
The rear intermittent wipe function is linked, among other things, to the operation of the windshield wiper
system. It will therefore be described in relation to the position of the combination switch (S4):
Combination switch (S4) position: OFF
The rear wiper is powered from KI. 15R: ON by operating the rear wiper/washer switch (S78) . Switching
on the wiper illuminates the LED on the rear wiper/washer switch (S78) and immediately causes the wiper arm
to perform one complete sweep before switching to intermittent wiping.
When the vehicle is traveling at speeds of
less than 100 km/h the wipe interval is 10 seconds
of 100 km/h or more the wipe interval is 5 seconds .
The wiper is turned off by reactivating the wiper/washer switch.
Combination switch (S4) position: Wiper speed 1 or 2
The rear wiper is activated from KI. 15R: ON using the rear wiper/washer switch (S78) .
Switching on the wiper illuminates the LED on the rear wiper/ washer switch (S78) and immediately
causes the wiper arm to perform one complete sweep before switching to intermittent wiping. The wipe
interval is 5 seconds .
Survey on wiper system
components (WS), location/
purpose/design/function GF82.30-P-9998GH
Rear wiper/washer switch GF82.30-P-4105GH
All Activity ModuleTo 30.11.99GF54.21-P-4100GH
As of 1.12.99GF54.21-P-4100GK
Tailgate wiper motor GF82.30-P-4105GH
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 42 © 2006 Mitchell Repair Information Company, LLC.
Page 1538 of 4133

The wiper is turned off by reactivating the wiper/washer switch.
The rear wiper switches on automatically from KI. 15R: ON when reverse gear is engaged. The wiper
operates continuously without delays until reverse gear is disengaged. Note: The LED on the rear
wiper/washer switch (S78) does not illuminate when vehicle is in reverse gear.
Combination switch (S4) position: Intermittent
When the combination switch (S4) is in the Intermittent position we must differentiate between vehicles
with and without rain sensors (code 345a) when describing the rear wiper function.
No rain sensor (no code 345a)
The rear intermittent wipe function is activated as follows:
By engaging reverse gear ; from KI. 15: ON . The wiper arm immediately performs one complete
sweep.
Then the rear wiper switches to intermittent wiping at a frequency half that of the front windshield
wiper until the vehicle is put into neutral or another gear.
By activating the rear wiper/washer switch (S78) ; from KI. 15R: ON . Switching on the wiper
illuminates the LED on the rear wiper/washer switch (S78) and immediately causes the wiper arm to
perform one complete sweep. Then the rear wiper switches to intermittent wiping at a frequency half
that of the front windshield wiper. The wiper is turned off by reactivating the wiper/washer switch.
The start of each wipe cycle is synchronized with the front wiper system.
With rain sensor (with code 345a)
The rear intermittent wipe function is activated as follows:
By engaging reverse gear ; from KI. 15: ON . The wiper arm immediately performs one complete
sweep. Then the rear wiper switches to intermittent wiping at a frequency equal to that of the front
windshield wiper until the vehicle is put into neutral or another gear.
By activating the rear wiper/washer switch (S78) ; from KI. 15: ON. Switching on the wiper
illuminates the LED on the rear wiper/washer switch (S78) and immediately causes the wiper arm to
perform one complete sweep before switching to intermittent wiping. The frequency is linked to the
frequenc
y of the front windshield wiper and is thus controlled by the rain (B38)sensor . NOTE: The LED on the rear wiper/washer switch (S78) does not illuminate when
the vehicle is in reverse gear.
NOTE: The LED on the rear wiper/washer switch (S78) does not illuminate when
the vehicle is in reverse gear.
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 43 © 2006 Mitchell Repair Information Company, LLC.
Page 1539 of 4133

The actual frequency is also a factor of the vehicle's speed of travel (see chart below).
The wiper is turned off by reactivating the wiper/washer switch.
The start of each wipe cycle is synchronized with the front wiper system.
Networking
Rain sensor (B38) and reverse signals are fed to the All Activity Module (AAM) (N10) via the engine
compartment CAN.
The settings of the rear wiper/washer switch (S78) are read directly by the All Activity Module (AAM)
(N10) .
The tailgate wiper motor unit (M6/4) is controlled directly by the All Activity Module (AAM, N10) .
The tailgate wiper motor unit (M6/4) comprises a relay and a cam-operated switch in addition to the
actual motor.
WINDSHIELD INTERMITTENT WIPE, FUNCTION - GF82.30-P-3003GH
MODEL 163
Function sequence
The interval wiping function is switched on to position (i) with the combination switch.
The input (pin A8) of the all-activity module (AAM, N10) is connected to c. 15 R .
The AAM immediately actuates the front wiper motor relay (F1k17) for max. 2 s. In wiper stage 1 power is
supplied to the wiper motor (M6/1) b
y the relay (pin a).
Vehicle speed Under 50
km/hVehicle speed 50 to 100
km/hVehicle speed 100 km/h
and higher
Frequency of Rear wiperOne twelfth of front
wiper frequencyOne tenth of front wiper
frequencyOne sixth of front wiper
frequency
Rear Wiper/Washer Switch -
Location/Task/ Design/Function GF82.30-P-
4105GH
All Activity Module -
Location/Task/Design/ Function GF54.21-P-
4100GK
Tailgate Wiper Motor -
Location/Task/Design/ Function GF82.30-P-
4105GH
Rain Sensor -
Location/Task/Design/FunctionVehicles with code
345a (rain sensor)
onlyGF82.30-P-
4103GH
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 44 © 2006 Mitchell Repair Information Company, LLC.
Page 1540 of 4133

Power is supplied to the motor by the cam switch and non-actuated contact of the relay F1 k17(pin b) until the
wiper arm has reached its park position. When the park position is reached the cam switch switches over. Then
the two motor connectors are short-circuited and the motor is braked by the eddy-currents.
Then the actual interval wiping starts. The described procedure is repeated for each interval.
Fig. 24: Identifying Windshield Intermittent Wipe Function
Interval actuation without code 345a (without rain sensor)
When the interval time is completed the AAM starts a new wiping procedure. The interval time is speed
dependent and is adjusted between 5 s when parked and 1 s at a speed of 180 km/h by the AAM.
Interval actuation as of 1.9.00 with code 345a (with rain sensor)
When c. 1 is ON: the rain sensor (B38) defines the wiping intervals .
The wiper motor relay (F1 k17) is actuated by the AAM at the intervals defined by the rain sensor (cf.
function sequence above). The relay switches off when c. 31 b (wiper not in park position) is recognized,
however, after 1 s (lock-up) at the latest.
In the event of heavy rain the relay remains actuated, the wiper operates as in stage 1.
Wiper motor,
location/purpose/design/function GF82.30-P-
4104GH
Safety switch-off (WS), functionas of 1.9.2000GF82.30-P-
3005GH
Anti-lock protection for wiper motor GF82.30-P-
4008GH
All-activity module (AAM),
location/purpose/ design/functionup to 30.11.99GF54.21-P-
4100GH
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 45 © 2006 Mitchell Repair Information Company, LLC.
Page 1541 of 4133

WIPER, FUNCTION - GF82.30-P-3004GH
MODEL 163
The function wiping windshield is switched in three stages with the combination switch (S4)
One-touch wiping - press switch lever upward to first catch position (t). The switch lever returns to the
basic position after being released.
Wiping stage 1 - press switch lever upward beyond first catch position (1).
Wiping stage 2 - press switch lever upward beyond second catch point (2).
A connector of the wiper motor (M6/1) is connected to circuit 15. The motor starts operating. When stage 2 is
switched on the other motor connection is switched. The motor operates with higher speed.
When switched back to the basic setting the motor is supplied with power by c. 15 via the non-actuated contact
of relay F1k17 (b) until the wiper arm has reached its park position. In this position, the cam switch brakes the
motor by short-circuiting (eddy-current brake)
Fig. 25: Identifying Wiper Function
as of 1.12.99GF54.21-P-
4100GK
Rain sensoronly with code 345a
(rain sensor)GF82.30-P-
4103GH
Anti-lock protection for wiper motor GF82.30-P-
4008GH
Wiper motor,
location/purpose/design/function GF82.30-P-
4104GH
All-activity module, up to 30.11.99GF54.21-P-
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 46 © 2006 Mitchell Repair Information Company, LLC.
Page 1542 of 4133

SAFETY SHUTOFF (WSA) - FUNCTION - GF82.30-P-3005GH
MODEL 163 Applicable as of 1.9.00
Safety shutoff
The intermittent wipe function is interrupted when the vehicle comes to a complete stop and at least one of
the front doors is open. Any wipe cycle in progress is completed before wipers come to a halt.
Wiping resumes when both front doors are closed and/or the vehicle is put into motion.
The safety shutoff therefore only operates when the vehicle is at a complete stop. This ensures that the
intermittent wiping feature remains available during driving even if a door jamb switch is defective.
ANTI-LOCK PROTECTION FOR WIPER MOTOR, FUNCTION - GF82.30-P-4008GH
MODEL 163
The all-activity module(AAM) (N10) recognizes that the wiper motor (M6/1) is locked up because of the
absence of signals from the cam switch.
If signals are not recognized for longer than 1 s the front wiper motor relay (F1k17) is no longer actuated.
The anti-lock protection is only effective in the function interval wiping . In other wiper stages the AAM does
not have influence on the wiper motor.
RAIN SENSOR - FUNCTION - GF82.30-P-4103-02GH
location/purpose/design/function4100GH
as of 1.12.99GF54.21-P-
4100GK
Extended activity module,
location/purposeas of 1.12.99GF54.21-P-
4106GH
Windshield Intermittent
Wipe - Function GF82.30-P-3003GH
Wiper motor,
location/purpose/design/function GF82.30-P-
4104GH
All-activity module (AAM),
location/purpose/ design/functionup to 30.11.99GF54.21-P-
4100GH
as of 1.12.99GF54.21-P-
4100GK
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 47 © 2006 Mitchell Repair Information Company, LLC.
Page 1543 of 4133

How it works
An infrared transmitter (2)sends infrared light to a lens (1) which directs the beam to the windshield (4) . The
intensity of the light reflected by the windshield is measured by an IR receiver (3)located at the opposite end of
the lens.
Dry windshield (Fig. A)
When the area around the rain sensor (B38) is dry nearly all of the light is reflected and the IR receiver
(3) measures a high level of light intensity.
Wet windshield (Fig. B)
When the reflection area is wet, some of the light is scattered away from the glass of the windshield. This
reduces the intensity of the reflected light and the IR receiver (3) measures a lower level of light intensity.
The light intensity measured by the IR receiver (3) provides a measure of the rain intensity on the windshield.
Lower light intensities indicate higher levels of rain intensity on the windshield.
Fig. 26: Identifying Infrared Transmitter And IR Receiver
Rain sensor data flow
The rain sensor (B38) networks with the All Activity Module (AAM, N10) via the engine compartment CAN.
More than
just a "rain sensor," the unit also comprises integrated light sensors for the vehicle lighting
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 48 © 2006 Mitchell Repair Information Company, LLC.
Page 1544 of 4133
system . Data from the light sensors is also sent to the All Activity Module (AAM, N10) via the engine
compartment CAN.
Power supply
Power is supplied to the rain sensor (B38) via KI. 15 so that these functions are available only when the ignition
is on.
RAIN SENSOR - LOCATION/TASK/DESIGN/FUNCTION - GF82.30-P-4103GH
MODEL 163 with code 345a Rain sensor
Fig. 27: Identifying Rain Sensor Location
Rain Sensor - LocationThe rain sensor (B38) is
adhered to the inside
surface of the windshield.
Rain Sensor - TaskThe rain sensor (B38)
assesses the rain
intensity on the
windshield and
automatically adjusts the
intermittent wiper speed.
In addition, light sensors
gauge ambient light
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 49 © 2006 Mitchell Repair Information Company, LLC.